Exploring interactions between anions and kinetically stable lanthanide complexes in aqueous solution

<p>This work utilises the interactions between lanthanide complexes and anions in solution to explore the nature of coordination chemistry in the f-elements, and to define fundamental behaviour in paramagnetic complexes, as well as investigating the factors responsible for ensuring high lantha...

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Bibliographic Details
Main Author: Routledge, J
Other Authors: Faulkner, S
Format: Thesis
Published: 2016
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Summary:<p>This work utilises the interactions between lanthanide complexes and anions in solution to explore the nature of coordination chemistry in the f-elements, and to define fundamental behaviour in paramagnetic complexes, as well as investigating the factors responsible for ensuring high lanthanide luminescence quantum yields.</p> <p>Chapter one describes characteristic lanthanide properties with a focus on luminescence and the current understanding of lanthanide complexes. Illustrating the response of luminescent lanthanide complexes to a range of analytes in aqueous solution. </p> <p>Chapter two explores the factors affecting luminescence quantum yield in arylacylDO3A complexes as well studying the pH behaviour of these species, showing that the whole energy transfer cascade involved in sensitisation of lanthanide luminescence must be considered when optimising the properties of lanthanide complexes.</p> <p>Chapter three describes the effect of fluoride binding in lanthanide tetra-amide complexes appended with fluorinated benzyl groups on the lanthanide crystal field, demonstrating that the effect of a strong axial donor on the overall ligand field can determine the nature of the magnetic anisotropy at the lanthanide centre. This in turn determines both the optical spectra and the NMR spectra of the complexes. The results obtained illustrate that the whole structure of the complex (and not just the donor set) need to be considered when defining the behaviour of the lanthanide complex.</p> <p>Chapter four investigates the interaction between fluoride and lanthanide complexes of the Lehn cryptand. In this case, the relatively symmetric donor set associated with the cryptand, combined with exchange between isomers, gives rise to small observed anisotropies in the absence of fluoride that are dramatically enhanced by fluoride binding. A range of fluoride responsive behaviour has been identified. </p> <p>Chapter five describes the synthesis and study of a group of halogenated phenacylDO3A lanthanide complexes. It is shown how such complexes respond to changes in cyanide concentration but are essentially inert towards fluoride as a consequence of the reduced residual charge on the lanthanide centre. The interaction with cyanide is assigned to the formation of a cyanohydrin which is assisted by the proximate lanthanide ion, which acts as a Lewis acid. </p> <p>Chapter six draws together the work described in earlier chapters. </p> <p>Chapter seven provides experimental procedures along with characterisation data for the compounds studied. </p>